QSPI: problems with a MX25R1635F or how to initialize the port pins?

[rgrr2]

Hi

data sheet of the nRF52840 states that the QSPI port pins should be initialized to "high drive".

I've experimented a little bit because I have problems with a Macronix Flash (MX25R1635F) which does not reliably work.  The DK-Chip from Macronix (MX25R6435F) is not a problem with the same firmware and a flash from OnSemi (LE25S161) works on our hardware as well.

To make the story short: I can do RDID of the MX25R1635F, but reading the status/config register of the MX25R1635F always shows zero.  Erasing also does not work.  The OnSemi works without problems.

I've already used all different SPI read/write modes, no success.  I've also tried to init the port pins with pullup.  Not a good idea, because the program than hangs.

So the question: how to setup the QSPI port pins properly?

Thanks & regards

Hardy

[rgrr2]

Replying to myself: I guess that the following could be a problem:

#define NRFX_QSPI_DEFAULT_CINSTR(opc, len) \
{                                          \
    .opcode    = (opc),                    \
    .length    = (len),                    \
    .io2_level = false,                    \
    .io3_level = false,                    \
    .wipwait   = false,                    \
    .wren      = false                     \
}

This is used e.g. in nrfx_qspi_mem_busy_check().

The Macronix has two different modes.  In one IO3 and IO4 are HOLD# and RESET#, in the other those are IOs (QEN).

Problem seems that one has to really put the Macronix into the QEN mode before all is working.

So still two question:

• how to init the QSPI port pins?
• is there any special reason, why io3_level/io4_level are set to "0"?

Regards

Hardy

[rgrr2]

Hi Simon

question remains open: any special reason why IO3/4 are set to "0"?  To my opinion this collides with /HOLD of most flash parts.  (at least my OnSemi / Macronix ;-))

Regards

Hardy